1. Field of the Invention
The present invention relates to a charged particle beam apparatus for identifying a predetermined position in a sample having a repeated pattern.
2. Description of the Related Art
In the analysis of a defect or failure in a semiconductor memory, it is required to identify a memory cell which has the defect or failure. Conventionally, a scanning electron microscope (SEM) has been used in order to identify the memory cell which has the defect or failure. Namely, a sample stage is displaced with a pitch corresponding to the pitch between the memory cells while making a visual inspection of the SEM image of the sample, thereby counting the memory cells from an edge of the sample.
In recent years, in accompaniment with the fine miniaturization of semiconductor memory devices, each memory cell has been becoming tremendously smaller and smaller in size. Accurately identifying a specific memory cell requires implementation of the stage displacement accuracy at the submicron level. The conventional scanning electron microscope, however, has not had a sample stage mechanism whose accuracy is so high as to be able to identify the memory cell.